The introduction of unwanted sounds is a common problem encountered in audio recordings. These unwanted sounds may occur acoustically at the time of the recording, or be introduced by subsequent signal corruption. Examples of acoustic unwanted sounds include the drone of an air conditioning unit, the sound of an object striking or being struck, coughs, and traffic noise. Examples of subsequent signal corruption include electronically induced lighting buzz, clicks caused by lost or corrupt samples in digital recordings, tape hiss, and the clicks and crackle endemic to recordings on disc.
We have previously described techniques for attenuation/removal of an unwanted sound from an audio signal using an autoregressive model, in U.S. Pat. No. 7,978,862. However improvements can be made to the techniques described therein.